The present invention copies with the problem of insufficient CPU performance and or bus bandwidth in computer devices, particularly when based on single core platforms, wherein multiple time critical applications have to be executed in parallel, one of these applications being a digital picture taking application. A computer device that is typically prone to said problem is e.g. a low or mid-end cellular phone, in which a cellular telecom stack and a still picture application are executed.
Document EP 1 691 272 A2 discloses an intelligent DMA in a mobile multimedia processor supporting multiple display formats. Methods and systems for processing video data are disclosed herein and include determining a first video format associated with video data to be displayed on a first video display communicatively coupled to a single mobile multiple media processor that supports a plurality of display formats. The single mobile multiple media processor may be integrated within a mobile device. An amount of the video data that is transferred from memory to the first video display, by a DMA controller, may be restricted based on the determined first video format associated with the video data to be displayed on a first video display. Only the restricted amount of the video data that is to be displayed by the first video display may be transferred from the memory to the first video display by the DMA controller.
The known method and device, however, do not take into consideration that the required bus bandwidth does not only depend on the video data transmitted from a memory to the first video display, but also depends on other applications running on the same device, resulting in a non-predictable available bandwidth for the video application. Hence, in the known device the video data either have to be restricted to such an amount that even in worst-case scenarios there is enough head room provided for transmitting the video data, or the transmission may fail.